Fresnel Filter

Description

A low-pass filter to improve the contrast of reconstructed images which is similar to the Paganin filter but can work on both sinograms and projections.

• Plugin documention and guidelines on use

Parameters

in_datasets:
    visibility: datasets
    dtype: "[list[],list[str]]"
    description:
        summary: A list of the dataset(s) to process.
        verbose: A list of strings, where each string gives the name of a dataset that was either specified by a loader plugin or created as output to a previous plugin.  The length of the list is the number of input datasets requested by the plugin.  If there is only one dataset and the list is left empty it will default to that dataset.
    default: "[]"

out_datasets:
    visibility: datasets
    dtype: "[list[],list[str]]"
    description:
        summary: A list of the dataset(s) to create.
        verbose: A list of strings, where each string is a name to be assigned to a dataset output by the plugin. If there is only one input dataset and one output dataset and the list is left empty, the output will take the name of the input dataset. The length of the list is the number of output datasets created by the plugin.
    default: "[]"

ratio:
    visibility: basic
    dtype: float
    description: Control the strength of the filter. Greater is stronger
    default: "100.0"

pattern:
    visibility: basic
    dtype: str
    description: Data processing pattern
    options: "['PROJECTION', 'SINOGRAM']"
    default: SINOGRAM

apply_log:
    visibility: basic
    dtype: bool
    description: Apply the logarithm function to a sinogram/projection before filtering.
    default: "True"

Key

visibility: The visibility level of the parameter
dtype: The type of data
description: A short explanation of the parameter
default: The default value
options: A list of permitted values
dependency: The name of the parameter and value which this parameter depends upon
range: A guide for the range of the parameter

Citations

Data processing methods and data acquisition for samples larger than the field of view in parallel-beam tomography by Vo, Nghia T et al.

Bibtex

@article{Vo:21,
title = {Data processing methods and data acquisition for samples larger than the field of view in parallel-beam tomography},
author = {Nghia T. Vo and Robert C. Atwood and Michael Drakopoulos and Thomas Connolley},
journal = {Opt. Express},
number = {12},
pages = {17849--17874},
publisher = {OSA},
volume = {29},
month = {Jun},
year = {2021},
doi = {10.1364/OE.418448}}

Endnote

%0 Journal Article
%T Data processing methods and data acquisition for samples larger than the field of view in parallel-beam tomography
%A Vo, Nghia T
%A Atwood, Robert C
%A Drakopoulos, Michael
%A Connolley, Thomas
%J Optics express
%V 29
%N 12
%P 17849-17874
%D 2021
%I Optical Society of America

API

class FresnelFilter

apply_filter(mat, window, pattern, pad_width)

make_window(height, width, ratio, pattern)

pre_process()

This method is called immediately after base_pre_process().

process_frames(data)

This method is called after the plugin has been created by the pipeline framework and forms the main processing step

Parameters

data (list(np.array)) – A list of numpy arrays for each input dataset.

setup()

This method is first to be called after the plugin has been created. It determines input/output datasets and plugin specific dataset information such as the pattern (e.g. sinogram/projection).